package com.atguigu.java;

import org.junit.Test;

/**
 * @author : leimingchao
 * @date Date : 2021年06月20日 14:50
 */
public class IDEADebug {

    @Test
    public void test() {
        String str = null;
        StringBuffer sb = new StringBuffer();
        sb.append(str);
        System.out.println(sb.length());
        System.out.println(sb);
        //抛异常:NullPointerException
        StringBuffer sb1 = new StringBuffer(str);
        System.out.println(sb1);
    }
}
